The desirability of incorporating antimicrobial or antibacterial agents into different types of surgical dressings has been evident for some time. Although numerous antimicrobials are available, most of these antimicrobial agents are either not suitable for contact with human skin, or they are very difficult to incorporate into an adhesive composition.
U.S. Pat. No. 3,579,628 discloses a film dressing which contains a composition which reacts with water to generate a bacteriostatic substance.
U.S. Pat. No. 3,983,209 discloses a method of applying an antimicrobial to a wound by incorporating an antimicrobial agent into a bioerodible polymer. The polymer may be incorporated into an absorbent carrier for application to the wound.
U.S. Pat. No. 4,310,509 discloses an adhesive composition which contains a polyvinylpyrrolidone-iodine complex and which is incorporated into a solvent-based adhesive for application to a flexible backing material to be used on human skin. In order to insure that the antimicrobial will be present on the skin-contact surface of the material, the dressing is uniformly dispersed through the adhesive layer of the product.
U.S. Pat. No. 4,323,557 discloses a process incorporating a solution of an iodide and iodine into a pressure-sensitive adhesive to be used in contact with human skin.
U.S. Pat. No. 4,340,043 discloses the incorporation of uniform amounts of silver sulfadiazine as an antimicrobial into an adhesive-coated material. The skin contact adhesive is, again, a solvent-based adhesive.
Although water-based, skin contact adhesives are known, they have not been used in products containing antimicrobials. Such water-based adhesives are generally not compatible with antimicrobials as the antimicrobials are often cationic in nature. The water-based, skin-contact adhesives contain anionic surfactants as emulsifiers which are not compatible with the cationic antimicrobials. Water-based, skin-contact adhesives have an advantage in manufacturing in that they do not use environmentally undesirable solvents but use water, which may be readily removed from the adhesive when the dressing is manufactured.
The prior art antimicrobial adhesive products mentioned above also require that the antimicrobial be uniformly distributed through the entire adhesive. This requirement insures that the antimicrobial will be available on the skin-contact surface of the adhesive when the product is used.
A dressing containing an antimicrobial adhesive in which the antimicrobial is affixed on the skin-contact surface and which would not migrate would be advantageous because less antimicrobial would be required and because there would be greater assurance that the antimicrobial would be present in the skin contact surface when the product was put into use.